Are way to repair a tiny leak in overflow seal?

So I keepy trying to get further in my used 120 gallon setup/build, and it just seems like one stumbling block after another.



So here is the latest. The one overflow box (tank has two) is leaking right along were it seals with the tank glass. It isn't a massive leak, but it drips water instantly along the seam about 3/4 of the way towards the top of the overflow.

I haven't filled the tank completely yet as I am still waiting on a new impeller for the pump I got from the same guy. I am starting to think that I inherited a nightmare.

Anything inside the overflow will get hidden eventually when I cover the glass sides of the tank to hide the drain and return pipes.

So is there anything I can do to seal that back up? If it was completely dry, I could attempt to re-silicone it, but with the drips, I don't see how it could seal up correctly and fresh silicone won't stick to cured silicone.

I am going out of town for a week starting on Monday, so if something needs to cure during that time, it won't be like I am missing out on being able to continue to set up the tank. Draining the tank would be a nightmare as I would need to put the live rock/live sand into containers with heat/flow, and with 150 pounds of rock and about 120 pounds of sand, that takes up a LOT of space.



Ideas anyone? Products that seal well under water for small drips, or should I drain down below the leak, cut away the silicone down to that level, clean it, and put a fresh bead of silicone there (and all the way up while I am at it to make sure that there aren't additional leaks higher up)?

 

Id drain it, cut the silicone and reseal it. A quick repair now could be a disaster later... Trust me

 

Completely drain it? I could see if it was a main tank seal, but it is just the top 4-5 inches of the one side of the overflow. Not that whole span, but right around that mark.

 

You could probably get away with draining it below the leak and being really careful not to get anything in the tank when you go over it. Im just saying it'd be easier now then after the tank is full up and running if your patch lets go.

 

if you cut the corner now and have a disaster later it is not going to be pertty, just think of it this way...



A. would you rather go out and buy 3 steralite 50-60 gal totes and house your live rock in it for a week and spend 4-5 hours setting it up and 30-40$ in $ to do this and fix the leak.



B. do the short term fix and have it completely seperate on you later and dump 75 gal on your floor while your at work. and then have to do all of step A anyways.


chances are someone grabbed the overflow when it was moved or it has been bumped with live rock at some point or it tweaked when it was moved

 

Thanks everyone. I will have to mull over the options today (partial vs. full drain) and decide so that I can start working on it either way tonight. I do have durso standpipes that the top of them is just a touch higher than the top of the overflow, so not a ton of water will go into the sump if a power failure happened (not 75 gallons, but I would guess, using a volume calculator for the length x width of the tank x the inches it would potentially drop, and then x 7.47 to get the water amount it would be just under 10 gallons). My sump is a 40 gallon breeder that when at operating level holds right around 22 gallons minus the skimmer, etc, but basically 18 gallons of "space" for a power outage. With the returns an inch or so under the top water level, it would drain about that much anyway, and that is assuming that the power went out right after it was topped off. I know, Mr Murphy and his stupid law.

Oh, and I already have the RTV-108. I bought some a few weeks back when I was making some minor changes to the sump I got from Big D. And I will be out all of next week for work, back for the weekend, and then gone for a 2nd week, so there will be plenty of curing time.

So I guess tonight the "fun begins..."